JPH0949709A - Method for measuring inclination/height of part and inspecting apparatus using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring an inclination/height with reducing speckle interferences, defocusing of optically cut images, and detection errors to foreign articles/flaws. SOLUTION: An incoherent light from a light source 1 is turned to a slit light via a collimator lens 2 and a slit 3 and projected perpendicularly to a surface of a part 10 through a projection lens 4. A slit image 5 is formed. An optical cut image of a diffraction light and a scattering light from the surface is formed by an image formation lens 20 at a TV camera 21, which is photoelectrically converted. A central position of the optical cut image is obtained for every scanning line at an image-processing part 30 thereby to obtain a regression line. An inclination/height of the part is obtained from an inclination of the regression line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component inclination / height measuring method and an inspection apparatus using the same, and more particularly, to an inclination / height positioning inspection after processing and assembling a magnetic head or the like. The present invention relates to an optimum tilt / height detection method and an inspection apparatus using the same.

[0002]

2. Description of the Related Art In a part manufacturing process and an assembling process, it may be indispensable to measure or inspect positioning accuracy during or after the process for the purpose of quality control. In such a case, there are many cases in which non-contact measurement is required depending on the material of the measurement object, the measurement environment, and the like. As one of such non-contact measuring methods, there is a light cutting method. In the light cutting method, it is possible to detect the continuous height of the sample by illuminating the sample with slit light and detecting the position of the reflected light. Therefore, it is possible to detect the height and inclination of the component after manufacturing or assembling the component, and it is generally applied as a measuring technique such as quality control and inspection process.

For example, there is a parts inspection device disclosed in Japanese Patent Laid-Open No. 62-127602. In the inspection device described above, the laser beam in the form of a slit is obliquely above the measuring component.
It is a technique of irradiating a beam and shooting a slit image of the upper surface of the measurement part with a TV camera arranged above and obtaining the inclination of the both ends of the part from the captured light section image. The technique is characterized in that a light section image optically conjugated with these inclined portions is omitted as inclination calculation data. Further, for example, Japanese Patent Laid-Open No. 4-181
There are three-dimensional shape recognition devices described in Japanese Patent Laid-Open No. 108 and Japanese Patent Laid-Open No. 149729/1993. The three-dimensional shape recognition device uses a light section image, and if the measurement symmetric object is an image on a steeply sloping surface and is not clear, move the TV camera to ensure diffused reflection light from the measurement symmetric object. It was the one to capture and obtain a clear real image.

[0004]

SUMMARY OF THE INVENTION In the above-mentioned conventional component inspection apparatus using oblique illumination, the laser beam is limited to a slit shape to obliquely illuminate the measurement component and the reflected light is imaged. It is configured to detect the missing by detecting the missing by performing window setting on the imaged slit image and cutting out by the means, and determining the position and inclination of the upper surface of the measurement part from the position and inclination of the cut out line. is there.

In this optical system, since a laser beam is used as illumination light, if the measurement surface has irregularities, the light section image causes speckle interference, and the light section image shows the surface shape of the component. May be discontinuous regardless of. Therefore, even if the missing parts, the inclination, and the height of the component are obtained from the light-section image, the surface shape of the component may be different, which makes it difficult to perform accurate inspection and measurement.

Further, by obliquely illuminating the measurement surface of the component, the incident angle of the illumination light has a constant angle. Therefore, when the component or height is displaced in the measurement direction, the illumination light is emitted on the component. The reflection position shifts. For this reason, the reflection position is also shifted in the optical axis direction of the detection system, which may cause a defocused image of the optical section. If the light-section image is defocused, the contrast of the image is lowered, and the accuracy of measuring the tilt and height is lowered.

Similarly, if there is a step on the part, slit light may or may not be illuminated on the step depending on the positioning error in the height measuring direction of the part. In this case, the height detection result may or may not include the step difference amount of the component. Therefore, there is a problem that it is difficult to accurately obtain the inclination and height when the stepped portions are irregular on the surface of the component.

Further, the window is set for the imaged slit image, and the image cut out by this window is a portion which is optically conjugate with the plane portion of the component. Therefore, if there is a foreign matter or a scratch on the surface of the component that is conjugate with the cut image, the light section image becomes discontinuous, and even if the center position of the light section image is calculated, a large amount of error will result. There was a problem. Further, since the light section image is obtained in a slit shape, there is a problem that only the two-dimensional shape can be measured and the inclination of the component can be detected in only one direction.

Further, the conventional three-dimensional shape recognition apparatus for moving a television camera is effective for preventing detection of a virtual image when a real image and a virtual image due to slit light are detected at the same time. However, the moving mechanism of the television camera is required, and the configuration becomes complicated. Further, since the measurement symmetry object is inclined, the incident angle of the slit light has a constant angle, as described above, and therefore when the measurement symmetry object is displaced, defocusing occurs, leading to a decrease in measurement accuracy. There was a problem.

In order to solve the above-mentioned problems of the prior art, the present invention prevents the speckle interference due to the surface irregularities of the component which is the object of measurement, and prevents the defocus of the light section image due to the displacement of the component. Provides a tilt / height measurement method that reduces the tilt detection error, detects the tilt two directions at the same time, and reduces the detection error even if there is a foreign object or scratch at the position of the slit image projected on the component. The first purpose is to do. A second object of the present invention is to provide an inspection device using the above-mentioned tilt / height measuring method.

[0011]

In order to solve the above-mentioned problems, the method for measuring the inclination and height of a component according to the first invention is such that the slit image formed by incoherent light is used as illumination light to measure the component. Vertical projection onto a surface, diffract and scatter on the measurement surface, the diffracted and scattered light is imaged by an image forming means, the image is photoelectrically converted by a photoelectric conversion means, and the photoelectric conversion is performed by an arithmetic means. This can be achieved by calculating the inclination and height of the component from the signal.

More specifically, the method for measuring the inclination and height of a component according to the first aspect of the present invention uses illumination light of a slit image of incoherent light to irradiate the measurement surface of the component vertically. , Low coherence, to prevent speckle interference due to the unevenness of the measurement surface, to prevent the asymmetry of the light section image, even if the component is displaced in the axial direction of the illumination light, the illumination light on the component Even if there is a positioning error in the component height measurement direction, the same position is illuminated, even if there is a step on the component surface, it is illuminated, and the effect of the component surface step on the height detection result is eliminated, and the illumination system The optical axis of the detection system is arranged perpendicularly to the optical axis of, and even if the component is displaced back and forth in the optical axis direction of the illumination system, the reflection position of the illumination light on the component is the focal depth of the detection system. It does not change in the direction, and the captured light section image is not defocused. Despite also the positioning error, always so that the high contrast is obtained by to obtain the slope correctly.

In order to solve the above-mentioned problems, a tilt / height measuring method for another component according to the first invention is such that the illumination light of a slit image formed by incoherent light is applied to a component surface and a component mounting reference surface. The image is vertically projected, and the diffracted and scattered light of the slit image from the component surface and the component mounting reference surface is imaged by the image forming means, the image formation is photoelectrically converted by the photoelectric conversion means, and the photoelectric conversion is performed by the computing means. This can be achieved by calculating the inclination and height of the component and the component attachment reference plane from the converted signal.

More specifically, the tilt / height measuring method for another component according to the first aspect of the present invention uses illumination light of a slit image formed by incoherent light on the component surface and the component mounting reference surface. By projecting the image vertically and diffracting and scattering light from the slit image on the component surface and the component mounting reference plane, a cut image of the component and a cut image of the component mounting reference plane are obtained. The thickness of the component sample can be obtained from the obtained difference in height.

Further, in order to solve the above-mentioned problems, a tilt / height measuring method for a further component according to the first invention is a bright / dark pattern formed by incoherent light as illumination light.
This can be achieved by using an image. Furthermore, it can be achieved by using a pattern formed by incoherent light and arranged in a checkered pattern as the bright and dark pattern image. Furthermore, the light and dark pattern image can be achieved by using a line-and-space pattern. Furthermore,
The calculation means can be achieved by removing the data of the point where the light amount of the image formation and the size of the image formation are peculiar from the calculation symmetry of the calculation means.

More specifically, in the tilt / height measuring method for a further component according to the first invention, a slit image projected on the component is a checkerboard-like bright / dark pattern image or a line-and-space pattern. By making a bright and dark pattern image of a plurality of slits, the tilt of the component can be detected from two directions. Further, a tilt / height measuring method of still another component according to the first aspect of the present invention is such that a light amount,
By eliminating the data having a peculiar image size from the calculation symmetry, it is possible to eliminate the error caused by the foreign matters and scratches on the parts.

In order to solve the above-mentioned problems, the component inclination / height measuring device according to the second aspect of the present invention is an illuminating means for illuminating a slit image formed by incoherent light perpendicularly to the measurement surface of the component. An image forming means for forming an image of the light diffracted and scattered by the slit image on the component, a photoelectric conversion means for photoelectrically converting the image formation, and an operation for calculating the inclination and height of the component from the photoelectric conversion signal. It can be achieved by including means.

In order to solve the above-mentioned problems, the tilt / height measuring apparatus for another component according to the second aspect of the present invention makes a slit image formed by incoherent light perpendicular to the component surface and the component mounting reference plane. Illuminating means for projecting, image forming means for forming an image of the light that is diffracted and scattered by the projected slit image on the component surface and the component mounting reference surface, and a photoelectric conversion means for photoelectrically converting the image formation. This can be achieved by including the component and the computing means for computing the inclination / height on the component mounting reference plane from the photoelectric conversion signal.

In order to solve the above-mentioned problems, a tilt / height measuring apparatus for a further component according to a second aspect of the present invention is the tilt / height measuring apparatus for any one of the above-mentioned components, wherein the slit image is: This can be achieved by using a bright and dark pattern image. In the device for measuring the inclination and height of the parts described in the preceding paragraph, this can be achieved by using a pattern arranged in a checkered pattern for the light and dark pattern image. In the above-described device for measuring the inclination and height of parts, it can be achieved by using a line-and-space pattern for the light-dark pattern image. In the tilt / height measuring apparatus for components described above, the arithmetic means achieves by removing the data of the point where the light amount of the image formation and the size of the image formation are peculiar from the arithmetic symmetry. You can

[0020]

DETAILED DESCRIPTION OF THE INVENTION Each embodiment of the present invention will be described in detail below with reference to FIGS. [Embodiment 1] First, a sample tilt height inspection apparatus in which a tilt / height measuring method according to an embodiment of the present invention is used will be described. FIG. 1 is a schematic view of a sample tilt / height inspection apparatus according to an embodiment of the present invention, FIG. 2 is a schematic view of a tilt / height measuring method according to an embodiment of the present invention, and FIG. Schematic diagram of Defocus based on oblique illumination, Fig. 4 is Fig. 3
Fig. 5 is a schematic diagram of reduction of vertical defocus by vertical illumination.
Is a schematic diagram of a position detection error based on a step, and FIG.
FIG. 7 is a schematic diagram of reduction in position detection error due to vertical illumination.

In all of FIGS. 1, 2, 3, 4, 5, and 6, the same reference numerals designate the same parts, and therefore 7 is an illumination system. In this illumination system 7, 1 is a light source and 2 is a collimator. Lens 3 is a slit, 4 is a projection lens. Reference numeral 25 denotes a detection system. In this detection system 25, 5 is a slit image, 10 is a component, 20 is an imaging lens, 21 is a TV camera, 30 is an image processing unit, 40 is a monitor, and 50 is a light section image. Is. β is the incident angle, and γ is the reflection angle.

First, the illumination system 7 will be described. As shown in FIG. 1, the illumination system 7 is arranged perpendicularly to the inclination and height measurement surface of the component 10, and its incident angle is 0 °. The light source 1 is arranged in the illumination system 7, and the light source 1
The light emitted by the collimator lens 2 becomes parallel light. Since the collimator lens 2 forms parallel light, the light source 1 and the slit 3 have an optical infinite positional relationship. Therefore, the light source 1 has the slit 3
Light up. In order to optically illuminate the camera, the distance from the light source 1 to the collimator lens 2 and
The distance from the collimator lens 2 to the slit 3 may be matched with the focal length of the collimator lens 2. The projection lens 4 projects an image of the slit 3 which is illuminated by color, on the component 10.

The detection system 25 forms the slit image 5 of the projected illumination light, and reflects, diffracts, and scatters it according to the surface condition of the component 10, and diffracted light and scattered light thereof are transmitted to the imaging lens 20. Let the light enter and let the TV display the light-section image only with the incident light.
It is formed on the image plane of the camera 21. This light section image is photoelectrically converted by the TV camera 21 and becomes an image. This image is input to the image processing unit 30. For example, in the case of the light section image shown on the monitor 40, the center position of the light section image is obtained for each scanning line. The center position of the light section image obtained for each scanning line is the position in the optical axis direction of the illumination system, which is a position optically conjugate with the light section image. Further, a regression line is obtained by using the center position of the light section image obtained for each scanning line, and the inclination of the regression line indicates the inclination of the component 10.

Next, the principle of measuring the inclination and height of the component will be described with reference to FIG. The light emitted from the light source 1 enters the collimator lens 2 and enters the slit 3.
Light up. The light transmitted through the slit 3 forms a slit image on the component 10 by the projection lens 4. On the component 10, of the reflected, diffracted, and scattered light, diffracted light and scattered light enter the imaging lens 20, and the incident light forms an image at a position conjugate with the component 10. This imaging position is shifted by M when the component 10 is lowered by ΔZ.

When the incident angle of the illumination system 7 is β, the detection angle of the detection system 25 is γ, and the magnification of the imaging lens 20 is m = b / a, the shift amount M is expressed by the following equation (1). To be done.

[Equation 1] Therefore, by obtaining the center position of the light section image 50,
The height of the component 10 can be detected. Further, the inclination of the component 10 can be detected by obtaining a plurality of centers of the light section image 50 in the longitudinal direction of the slit image 50 and obtaining regression lines thereof.

The functions of the inclination / height measuring method and the inclination / height measuring device configured as described above will be described with reference to FIGS. First, the function of illuminating the measurement surface of the component 10 perpendicularly will be described. An error caused by the conventional oblique illumination shown in FIG. 3 will be described. As shown in FIG. 3, when the component 10 is obliquely illuminated with an incident angle of β and the optical system is set with a detection angle of γ, when the component 10 descends by Δz, the oblique illumination light is reflected by the component 10. The position to be moved is shifted by Δx in the optical axis direction of the detection system 25. This shift amount Δx is obtained by the following equation (2).

[Equation 2]

When the shift amount Δx is present, the slit image 5 formed on the component 10 is the default in the detection system 25.
I'm going to waste. If the slit image 5 is defocused, the contrast of the light section image 50 is lowered, which causes a large detection error. As the allowable value of this defocus amount,
Generally, the depth of focus DOF is used. The depth of focus DOF is obtained by the following equation (3), where λ is the wavelength of the illumination light and NA is the numerical aperture of the imaging lens.

(Equation 3) Therefore, in the oblique illumination optical system, the defocus amount is determined according to the incident angle β of the illumination system 7, the detection angle γ of the detection system 25, and the movement amount Δz of the component 10, and there is a case where the defocus amount deviates from the depth of focus. Sometimes. Therefore, the detection error due to the defocus may be large.

Next, with reference to FIG. 4, the reduction of the detection error caused by the defocus will be described. As shown in FIG. 4, the optical axis of the illumination system 7 is set perpendicular to the measurement surface of the component 10, that is, the incident angle 0 ° and the optical axis of the detection system 25 are set perpendicular to the measurement surface of the component 10. To do. With this setting, even if the component 10 is displaced, the reflection position on the component 10 is unchanged since the shift amount Δx = 0 in the optical axis direction of the detection system 25. Therefore, the detection error caused by the defocus does not occur, and the measurement accuracy is improved. However, when the incident angle β becomes small, Cos β of the denominator shown in the formula [1] becomes large, and Sin (β + γ) of the numerator becomes small, so that the detection sensitivity of the optical system decreases. When the incident angle β becomes 0 °, the detection sensitivity of the optical system becomes 0.

Further, other functions will be described with reference to FIGS. As shown in FIG. 5, in the conventional technology,
When the component 10 is obliquely illuminated with an incident angle of β and the optical system is set with a detection angle of γ, when the component 10 descends by Δz, the position where the oblique illumination light is reflected by the component 10 is the sample 10
It will be in a different position on top. Further, when the component 10 has a step Δz _1, it is the same as when the component 10 moves by the amount Δz ₁ . Now, when the component 10 descends by Δz and is reflected by a step portion which is lower by Δz ₁ , the detected image 50 moves by M ₁ . If the magnification of the imaging lens 20 is m = b / a, this M ₁ can be calculated by the following equation (4).

(Equation 4)

Since M ₁ is the total movement amount of the movement amount Δz of the component 10 and the step amount Δz ₁ of the component 10, if the step amount Δz ₁ is unknown, the movement amount of the component 10 is accurately obtained. I can't. On the other hand, as shown in FIG.
The optical axis of the illumination system 7 is set perpendicular to the measurement surface of the component 10, that is, the incident angle is set to 0 °, and the optical axis of the detection system 25 is set to the component 10.
If it is set to be perpendicular to the measurement plane, the reflection position on the component 10 does not change even if the component 10 is displaced parallel to the illumination optical axis, and the displacement of the component 10 regardless of whether there is a step or not. The quantity Δz can be accurately determined. However, the part 1
The shift amount M ₂ of the light section image 50 due to the displacement Δz of 0 is M ₂
= Δz × m × Sinγ. In the above equation, if γ = 90 °, then M ₂ = Δz × m. That is, when the detection angle γ is 90 °, it is obtained by the product of the displacement amount Δz of the component 10 and the magnification m of the detection system 25.

Next, the calculation in the image processing unit 30 will be described with reference to FIG. FIG. 7 is a calculation flowchart of the height and inclination of the component in the image processing unit. As shown in the calculation flowchart of FIG. 7, the light section image 10 imaged by the TV camera 21 is input to the image processing unit 30 in S ₁ . This image size is 512Pix x 512Pix
And In this image, the lateral direction of the slit is X
These are the coordinates, and the slit longitudinal direction is the Y coordinate.

Next, in S ₂ , filtering is performed. That is, after the input image, an image smoothing process such as average value filtering is performed in order to reduce the sampling error of the input image. Next, in S ₃ , singular point removal is performed. That is, when there is a foreign matter or a scratch on the component 10, the light section image 50 is detected as a discontinuous image, and therefore, these singular points, for example, the processing for excluding the peculiar Y-direction scanning line from the subsequent calculation targets. Is done.

Next, in S ₄ , the waveform center position is obtained using the waveform cut out for each scanning line in each Y direction. When the height of the waveform at the position of the coordinate X is Ix and the center position of the waveform is the center of gravity of the waveform, the following formula (5) is obtained.

(Equation 5) Xc ₁ to Xc ₅₁₂ is obtained for all the scanning lines with the waveform center position obtained above as Xc. Each Xc represents the height of the position of the component 10 which is optically conjugate with each scanning line.

Next, in S ₅ , the regression line Y = a is obtained by using the respective waveform center positions Xc obtained for each scanning line.
Find X + b. As a calculation method for obtaining this regression line, a least square method is generally used. Obtained regression line Y = a
Of X + b, the inclination a is the inclination of the component 10, and the cutting edge b is Y.
The height of the component 10 at a position conjugate with the coordinate 0 is shown. By the above image processing, the inclination and height of the component 10 can be obtained at the same time.

[Second Embodiment] Next, another embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 4 is a schematic view of an inspection device used in a tilt / height measuring method according to another embodiment of the present invention, and this embodiment describes a device for assembling accuracy of parts.
In the figure, the same reference numerals as those in FIG. The new code will be described. 11 is a component chuck, 5
Reference numeral 1 is an optical cut image of the component chuck, and α is the inclination of the component 10 and the component chuck 11. Since the configuration shown in FIG. 8 is the same as the configuration shown in FIG. 1, a brief description will be given, and the description will focus on the characteristic part.

As shown in FIG. 8, the component 10 as the measurement sample is attached to the component chuck 11. The illumination system 7 is arranged perpendicular to the tilt and height measurement surface of the sample 10, and its incident angle is 0 °. When the distance from the light source 1 to the collimator lens 2 and the distance from the collimator lens 2 to the slit 3 are matched with the focal length of the collimator lens 2, the light emitted from the light source 1 is collimated by the collimator lens 2. Therefore, the light source 1 and the slit 3 have an optical infinite relationship, so that the slit 3 is illuminated with a color.

The color-illuminated slit 3 forms a slit image 5 on the component 10 and the component chuck 11 by the projection lens 4. The illumination light that forms the slit image 5 is reflected, diffracted, or scattered according to the surface states of the component 10 and the component chuck 11. These reflected light, diffracted light,
Of the scattered light, a light-section image of only the light incident on the imaging lens 20 is formed on the imaging surface of the TV camera 21. The formed light-section image is as shown on the monitor 40.
0 and a light cut image 51 of the component chuck are formed.
The inclination α of the component 10 and the component chuck 11 is obtained by obtaining the inclinations of the two light-section images by the image processing unit 30. Similarly, it is possible to obtain the thickness of the component 10 by obtaining the height of each of the two light section images and calculating the difference between the two.

[Third Embodiment] Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram of an inspection device used in a tilt / height measuring method according to still another embodiment of the present invention.
1 shows an embodiment of the invention in which the inclinations of parts are simultaneously obtained in two directions. Since the configuration shown in FIG. 9 is the same as the configuration in FIG. 1, common parts will be briefly described, and characteristic parts will be mainly described. In the figure, the same reference numerals as those in FIG. Only new codes will be described.
Reference numeral 60 is a checkered light-dark pattern, 61 is a collimator lens, 62 is a projection lens, 65 is an image of the checkered light-dark pattern, xy is a plane including the surface of the sample part, α
₁ is an angle between the xy plane and the drawing, and α ₂ is an angle between the xy plane and a horizontal plane orthogonal to the drawing.

First, the light emitted from the light source 1 of the illumination system 7 is
The collimator lens 2 illuminates the checkered bright and dark pattern 60 with a color. The bright / dark pattern 60 is projected as a checkered bright / dark pattern image 65 on the component 10 via the collimator lens 61 and the projection lens 62. This projection optical system is called a telecentric optical system. in this way,
By setting the telecentric optical system, the component 1
Even if 0 moves in the optical axis direction of the illumination system 7, the center of the image 65 of the checkered bright and dark pattern remains unchanged.

Of the checkered bright and dark pattern image 65 projected on the component 10, the illumination light forming the bright portion is the component 1.
The light is diffracted and scattered on 0 and enters the imaging lens 20 of the detection system 25. Here, the detection angle γ of the detection system 25 is set to γ <90 °. The bright / dark pattern image 55 formed on the imaging surface of the TV camera 21 by the detection system 25 represents the three-dimensional shape of the component 10. The image representing the three-dimensional shape is taken into the image processing unit 30, and the interval between the center positions of the bright and dark pattern images 55 is calculated, so that α ₁ of the component 10 is calculated.
And the inclination in the α ₂ direction can be detected.

Next, the principle of detecting the inclinations in the α ₁ and α ₂ directions will be described with reference to FIG. FIG.
0 is an explanatory view of the detection principle in the inspection device of FIG. For example, if the intervals of the checkered pattern 60 are uniform, the center 55a of either the dark or bright pattern of the bright and dark pattern image 55 on the imaging surface is defined as 55a. The distances in the x direction between the respective pattern center positions 55a are l ₁ , l ₂ ,
l ₃ , l ₄ and l ₅ , and the y-direction intervals are m ₁ , m ₂ , m ₃ ,
If m ₄ and m ₅ are satisfied, the measurement surface of the component 10 is a smooth surface, l ₁ = l ₂ = l ₃ = l ₄ = l ₅ = l, m ₁ = m ₂ = m ₃ = m
_The relation is ₄ = m ₅ = m. Now, when the inclinations in the α ₁ and α ₂ directions are both 0 °, and the intervals between the pattern centers 55a are l and m, the inclinations of the component 10 in the α ₁ and α ₂ directions at this time are respectively. It can be obtained by the following equations (6) and (7).

(Equation 6)

(Equation 7)

[Fourth Embodiment] Next, still another embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 1 is a schematic diagram of an inspection device used in a tilt / height measuring method according to still another embodiment of the present invention. FIG.
The first example is a case where light and dark patterns are arranged in a line-and-space pattern as the light and dark patterns projected on the component 10. In the figure, the same reference numerals as those in FIG. 1 are the same parts, and thus the repetitive description will be omitted and only new reference numerals will be described. 3a is a line-and-space pattern of light and dark patterns, 5
Reference numerals 0a, 50b, and 50c are light section images.

The bright and dark pattern 3a in the line-and-space shape illuminated by the caller has an opening in the bright portion and a light-shielding portion in the dark portion. The light / dark pattern 3a is projected on the component 10, and the detection system 25 detects a light section image. As shown in FIG. 11, the light-dark pattern 3a has three openings,
Three detected light section images, 50a, 50b, and 50c, are also obtained. By detecting the respective inclinations, it is possible to detect the inclinations of the component 10 in two directions, as described in the above [Third Embodiment of the Invention].

[0044]

As described above in detail, according to the inclination / height measuring method and the structure of the inspection apparatus using the same according to the present invention, since incoherent light with low coherence is used as the illumination light, Speckle interference due to unevenness of parts does not occur,
This has the effect of preventing the asymmetry of the light section image. Further, by irradiating the shape measurement surface of the component with slit light vertically, even if the component is displaced back and forth in the illumination optical axis direction, the illumination light reflection position on the component does not shift, and the same. Has the effect of being a position. Further, since the illumination light reflection position on the component is the same, even if there is a step on the component, the slit light is not illuminated or not illuminated on the step portion, and there is no component positioning error. Even if there is an irregular step on the surface of the component, the effect of the component step on the height detection result can be prevented, and the inclination can be accurately obtained. Also, by arranging the optical axis of the detection system perpendicularly to the optical axis of the illumination system, even if the component is displaced back and forth, the illumination light reflection position on the component will not be in the focal depth direction of the detection system. It is invariable, and has the effect of preventing defocusing of the captured light section image. Further, since no defocus occurs, the light section image detected by the detection system always has a high contrast image regardless of the positioning error of the sample, and has the effect of stabilizing the inclination and height measurement accuracy. Further, regarding the calculation of the sample shape from the detected image, by removing the data having a peculiar amount of light of the image and the size of the image from the calculation symmetry, the error caused by the foreign matter or scratches on the component is eliminated, and the inclination, It has the effect of stabilizing the height measurement accuracy. Due to the above, the inclination and height measurement accuracy of parts is improved, the inclination of the processing and assembling process of parts, the reliability of height inspection can be improved, and the inclination and height measurement method that improves the yield of products and it. It is possible to provide an inspection device using the.

[Brief description of drawings]

FIG. 1 is a schematic view of a sample tilt / height inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a tilt / height measuring method according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of defoccus based on oblique illumination.

FIG. 4 is a schematic diagram of reduction by vertical illumination for the defocus of FIG.

FIG. 5 is a schematic diagram of a position detection error based on a step.

FIG. 6 is a schematic diagram for reducing the position detection error of FIG. 5 by vertical illumination.

FIG. 7 is a calculation flowchart of the height / inclination of a component in the image processing unit.

FIG. 8 is a schematic diagram of an inspection device used in a tilt / height measuring method according to another embodiment of the present invention.

FIG. 9 shows a tilt according to still another embodiment of the present invention.
It is a schematic diagram of the inspection apparatus used for the height measuring method.

10 is an explanatory diagram of a detection principle in the inspection device of FIG.

FIG. 11 is a schematic diagram of an inspection apparatus used in a tilt / height measuring method according to still another embodiment of the present invention.

[Explanation of symbols]

1 ... Light source, 2 ... Collimator lens, 3 ... Slit, 3a
Is a line-and-space pattern, 4 ... Projection lens, 5 ... Slit projection image, 7 ... Illumination system, 10 ... Parts,
11 ... Component chuck, 20 ... Imaging lens, 21 ... TV camera, 25 ... Detection system, 30 ... Image processing part, 40 ... Monitor, 50, 50a, 50b, 50c ... Light section image, 51 ...
Light cut image of the component chuck, 60 is a checkered pattern.
, 61 is a collimator lens, 62 is a projection lens, and 65
... Image of checkered pattern, d ... Thickness of component 10, x-
y: a plane including the surface of the component that is the sample, an angle formed by the α ₁ ... xy plane and the drawing, an angle formed by the α ₂ ... xy plane and a horizontal plane orthogonal to the drawing, β ... an incident angle , Γ ... Reflection angle

 ─────────────────────────────────────────────────── ─── Continued front page (72) Hitoshi Kubota, Hitoshi Kubota, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture, Ltd.Institute of Industrial Science and Technology, Hitachi, Ltd. Hitachi, Ltd. Personal Media Equipment Division

Claims (12)

[Claims] 1. A method of measuring inclination and height of a component, wherein illumination light of a slit image formed by incoherent light is used.
Vertically projecting onto the surface of the component, and image forming the diffracted light and scattered light of the illumination light from the surface of the component by the image forming means,
A method for measuring the inclination / height of a component, characterized in that the image formation is photoelectrically converted by a photoelectric conversion unit, and the inclination / height of the component is calculated from the photoelectric conversion signal by a calculation unit. 2. A method of measuring inclination and height of a component, wherein illumination light of a slit image formed by incoherent light is used,
The component surface and the component mounting reference plane are vertically projected, and the diffracted light and scattered light of the illumination light from the component surface and the component mounting reference surface are imaged by the image forming means, and the image is formed by the photoelectric conversion means. Inclination / height of the component characterized by performing photoelectric conversion and calculating the inclination / height on the component and the component attachment reference plane from the photoelectric conversion signal by the calculating means.
Height measurement method. 3. The component inclination / height measuring method according to claim 1, wherein a bright / dark pattern image formed by incoherent light is used as the illumination light. Tilt and height measurement method. 4. The method for measuring the inclination and height of a component according to claim 3, wherein a pattern formed by incoherent light and arranged in a checkered pattern is used as the bright and dark pattern image. And how to measure the tilt of the part. 5. The method for measuring the inclination and height of a component according to claim 3, wherein a line-and-space pattern is used as the bright-dark pattern image. Method. 6. The tilt / height measuring method for a component according to claim 1, wherein the amount of light of the image and the size of the image are unique.
Is removed from the calculation symmetry of the calculation means. 7. A component inclination / height inspection apparatus, wherein an illumination means for vertically projecting a slit image formed by incoherent light onto a measurement surface of the component, and the projected slit image is the component surface. An image forming means for forming an image of the light diffracted and scattered above; a photoelectric converting means for photoelectrically converting the image forming; and a calculating means for calculating the inclination / height of the component from the photoelectric conversion signal. Inclination of characteristic parts
Height inspection device. 8. A component inclination / height inspection apparatus, wherein an illumination means for vertically projecting a slit image formed by incoherent light onto a component surface and a component mounting reference plane, and the projected slit image. An image forming means for forming an image of light diffracted and scattered on the surface of the component and the reference surface for attaching the component, and a photoelectric conversion means for photoelectrically converting the image.
An inclination / height measuring device for a component, comprising: an arithmetic unit that calculates the inclination and height of the component and the component attachment reference plane from the photoelectric conversion signal. 9. The inclination / height measuring device for a component according to claim 7, wherein a bright / dark pattern image is used as the slit image. . 10. The device for measuring the inclination and height of a component according to claim 9, wherein a pattern arranged in a checkered pattern is used for the bright and dark pattern image. . 11. The component inclination / height measuring device according to claim 9, wherein a line-and-space pattern is used for the bright-dark pattern image. apparatus. 12. The device according to claim 7, 8, 9, 10, or 11, wherein the computing means has a specific light amount of the image formation and a size of the image formation. A device for measuring the inclination and height of parts, which removes data at various points from the calculation symmetry.